Pharmaceutical researchers have discovered in recent years that the neurons of the brain which contain monoamines are of extreme importance in a great many physiological processes which very strongly affect many psychological and personality-affecting processes as well. In particular, serotonin (5-hydroxytryptamine; 5-HT) has been found to be a key to a very large number of processes which affect both physiological and psychological functions. Drugs which influence the function of serotonin in the brain are accordingly of great importance and are now used for a surprisingly large number of different therapies.
The early generations of serotonin-affecting drugs tended to have a variety of different physiological functions, considered from both the mechanistic and therapeutic points of view. More recently, it has become possible to study the function of drugs at individual receptors in vitro or ex vivo, and it has also been realized that therapeutic agents with a single mechanism of action are often advantageous to the patient. Accordingly, the objective of research now is to discover not only agents which affect only functions of serotonin, but agents which affect only a single function of serotonin, at a single identifiable receptor.
The present invention provides compounds which have highly selective activity as antagonists of the serotonin 1.sub.A receptor.